Unit 7: “The States of Matter” – Chapters 13 &14

 Internet Resources

INTRODUCTION:    In our everyday lives the matter that we encounter can be classified in one of three states, solid, liquid or gas.  (There is a fourth and even fifth state of matter but these are not part of our everyday existence.  The fourth state is plasma and the fifth state is speculated as the state of matter in a neutron star or black hole.)  Chemists have developed the kinetic theory of matter with which they describe the behavior of the particular state in terms of the behavior of particles of matter.  For example, gaseous particles are far apart from each other and colliding with no attraction between the particles, whereas the particles in a liquid or solid state are in contact with each other and sticking together to various degrees.  Gases, in particular, have been the subject of separate study for more than 300 years.  Gases have received this attention because their behavior can be idealized.  This means that scientists can make some assumptions about gases and the particles that make them up.  Because of the reasonable nature of these assumptions, scientists have been able to model gas behavior with a simple mathematical relationship.  In this unit we will learn about the kinetic theory of matter and apply its explanations to the three common states.  We will also examine the simple relationship between the volume, pressure, amount and temperature of a gas, called the Ideal Gas Law. 

OBJECTIVES:  As you study this unit, you should be able to do the following:

1. Describe the kinetic-molecular theory, and explain how it accounts for observed physical behavior in solids, liquids and gases. (Chapter 13 and 14.1)

2. Explain what gas pressure means, describe how gas particles cause pressure, and be able to convert between different units of pressure. (13.1)

3. Discuss the relationship between temperature and kinetic energy. (13.1)

4. Describe the nature of liquids and the factors that determine their physical properties. (13.2)

5. Compare the four main categories of solids and the properties they exhibit as related to the bonding that hold their particles together. (13.3)

6. Describe vaporization, condensation, boiling, freezing and melting in terms of particle behavior and energy. (13.2 & 13.4)

7. Identify the features of a phase diagram of a pure substance. (13.4, essay assignment)

8. State and describe the various “intermolecular forces” that draw molecules together.  (***Note: This topic takes us back to Chapter 8 section 4***)

9. Define and describe the four primary variables necessary to measure a gas. (14.1)

10. State the gas laws, give their mathematical relationships and describe the relationships in terms of the kinetic molecular theory.  (Boyle’s Law, Charles’ Law, Gay-Lussac’s Law, the Combined Law) (14.2)

11. Discuss the significance of the ideal gas law, pointing out the assumptions behind the law.  Compare ideal and real gases. (14.3)

12. Calculate an unknown quantity using the Ideal Gas law. (14.3)

13. Be able to do stoichiometric calculations involving gases. (worksheet and lab)

14. Discuss gas mixtures and employ Dalton’s Law of Partial Pressures as well as Graham’s Law of Effusion.  (14.4)

LEARNING ACTIVITIES:

To learn about objectives 1-8:

• READ Chapter 13, pp. 384-406.

• READ and PERFORM “Observing and Measuring the Triple Point of Dry Ice” lab sheet.

• EXPLORE interactive phase diagram at: http://titanium.fullerton.edu/shock/PHASED.htm 

• WRITE essay according to the CPR assignment on “Interpreting Single Substance Phase Diagrams.” (Maximum 300 words) found at CPR site: http://cpr.molsci.ucla.edu/cpr/cpr/login.asp

• The Essay Assignment:

  Write an essay of maximum 300 words on the interpretation of single substance phase diagrams and the nature of the three phases found in a phase diagram. In the essay you should address all of the issues raised in the guiding questions listed below. A brief outline of the important points to cover is as follows:

  • Explain what the phase diagram of a single substance represents and describe the diagram with respect to the location of all three regions.
  • Describe the activity of the particles in each of the three regions.
  • Describe what you observed in the constant pressure exploration.
  • Explain what happened during the constant temperature exploration.

  Guiding Questions:
   

  1. What does a phase diagram represent?
  2. What is the significance of the regions of a phase diagram?
  3. How is a typical phase diagram laid out? Where are the three regions relative to each other? What other important features are present?
  4. What is the nature of the particles' motion, organization and proximity in the three phases?
  5. What are the particles doing at a phase boundary?
  6. Where do multiple phases exist at the same time?
  7. What changes occur in the piston and cylinder diagram as the temperature or pressure changes?

   

• WRITE answers to end of the chapter question #s 27, 30, 31, 34, 35, 36, 39, 44, 47, 48, 49, 52, 63 found on pp. 407-409.

To learn about objective 9-14:

• READ Section 13-1; pp. 385-389, and Chapter 14; pp. 413-436.  See objectives for specific section.

• COMPLETE worksheet, “Ten Elementary Gas Law Problems.”

• READ and PERFORM “Getting the Volume Right” Lab exercise.

• WRITE answers to end of the chapter question #s 40, 43, 46, 48, 49, 55, 57, 58, 60 found on pp. 439-440.

To make sure you understand the objectives for this unit:

1. ASK me, the teacher, any lingering QUESTIONS

2. Gas Law chapter review problems.  Click here.

3. TAKE the Unit’s Self-Test

CPR Essay due: Friday February 29, 2008 by 11:45 pm on the CPR site.

CPR Final Assignment completion date: Friday. March 7, 2008 by 11:45 pm.   

GO TO SELF-TEST